Self-sealing tube insert



1-952 H. SCHULTZ 2,620,830

SELF-SEALING TUBE INSERT? Eiledfeb. 1B, 1950 INVENTOR. HERMN SCHULTZ AT T ORNEYS Patented Dec. 9, 1952 UNITED STATE'SPATENT optics Herman Schultz New York, N. Y. 7 Application February 18, 1950, Serial No. 144,949

This invention relates to self sealing tube inserts, and more particularly to an insert tube having an outer compressible sealing coating for replacing corroded or pitted tube sections in surface condensers, heaters, heat exchangers and the like.

In well known types of equipment such as condensers and the like, water as a coolant is used under high velocities thereby producing eddying currents, electrochemical action and other damaging effects at the inlet end of and around the face of the condenser tubes and at the front of the tube sheets. Heretofore, replacer tube sections have been used in which there are provided inserts with water absorbing packing or non-compressible surface coatings. In the first case, there is no protection against corrosion from water since the packing retains the water. In the latter case, there is no provision for contraction or expansion due to temperature differences of the tubes and coolant thereby resulting in the formation of cracks in the surface coating. In neither case is there any effective protection against pitting or cor rosion of the inlet end of the tubing.

With the above and other disadvantages in view, it is an object of my invention to provide a self sealing insert tube for condensers and the like which is resistant to corrosion.

Another object of the present invention is to provide a self insert replacer tube for condensers and the like, having a corrosion resistant compressible coating to allow for contraction and expansion of the condenser tubes.

Still another object of the present invention is to provide a self sealing tube insert which is water resistant and adapted to prevent pitting and corrosion of the tubes and tube sheets in condensers, heat exchangers, and the like.

Other objects and features will become apparent from the hereinafter following description taken in conjunction with the accompanying drawing in which there is shown a fragmental, partial view of a preferred embodiment of the invention.

In'the drawing, similar reference characters denote like parts throughout.

A tube sheet or header I is provided containing a plurality of tubes II. For purposes of illustration, a fragmental section of the header I 0 and of the tube is shown. Said tube II is of the usual type and length and is flared at the head portion I2 in order to offset as much as possible any deleterious action on th tube in said area.

2 Claims. (01. 138-497) In order to avoid or offset any chemical and/or other deleterious action on. the face of the. tube sheet, the flared portion if of the tube, and on th inner face I3 of tube H, there is provided an insert I4 which is adapted to fit in tube ll. Said insert I4 is made of a material highly resistant to corrosion, such as brass and the like. Furthermore, the insert is of a shape conforming with tube II and has an outwardly flared portion I6 to fit against flared portion I2 of said tube II. It will be noted that the thickness of the frontal portion of the tube I I is somewhat lesser than that at the central portion. The insert is provided with an external coating ll of any suitable compressible material whose thickness increases progressively from the inner end to the outer flared end I6 of the insert forming a thickened flared portion l8. Said insert is coated, bonded, sprayed or shielded with an elastic or compressible substance such as natural rubber, neoprene, duprene, vinylite derivatives, polythene or similar elastomeric substances, which provide for expansion and con-- traction of the insert I4 and the tube l3 while: at the same time preventing corrosion of tube I3. It will be noted that insert I4 is so designed that the thickness of coating I! is progressively greater toward the outside or flared end I 8 of said insert. Also, the outside overall diameter of coating I1 is slightly larger than the inside diameter of tube I3, so as to permit forming a tight fitting junction of the insert with the interior of tube I3. The insert is easily forced into tube I3 by first lubricating the coating I? of compressible material.

An insert of the type described and illustratedherein automatically seals any leaks in tube sheet I El and tube I3 and is so flared With respect to said tube I3 that there is an easy, smooth flow of the water or coolant thereby preventing eddying and localizing electrolytic action of the metal parts. A tube according to my invention prevents any accumulation of interstitial moisture and at the same time allows for expansion and contraction of the contacting parts. Furthermore, there is a mechanical compression of the coating due to the difference in sizes. The material is bonded to the insert to permit its easy installation into the tube I3. Such tubes made according tomy invention find their greatest application in replacing insert tubes heretofore used. Said inserts are particularly suited for use in tubes II which have been subjected to previous wear or corrosion of the forward or flared end I2.

Having described an illustrative embodiment of the invention, it is pointed out that various changes and modifications therein may be made without departing from the invention as set forth in the following claims.

I claim:

1. An insert tube for condensers and the like, comprising a corrosion resistant metal tubular member having an outwardly flared end portion, the exterior of said member being coated end to end with a lubricatable water and corrosion resistant compressible material bonded thereto, the thickness of said material on the member progressively increasing toward the flared portion thereof, said member wit-h the material thereon having an overall diameter slightly large-r than the inner diameter of the tubes in the condenser into which said insert is lodged whereby upon insertion into a condenser tube, the material is compressed and a tight leakage proof seal is formed therewith.

2. The combination with a tube wall and condenser tube therein, said tube having an outwardly flared end extending from and abutting the outside face of the wall, of an insert salvage corrosion resistant, metal tube adapted to fit into the condenser tube and having an outwardly flared portion abutting the flared end of the first '4 tube, said insert tube having an external coating of corrosion and heat resistant compressible material bonded thereon adapted to slide against the interior of the condenser tube, the overall diameter of the insert tube and the coating being slightly larger than the inner diameter of the condenser tube, whereby upon insertion into a condenser tube, the material is compressed and a tight leakage proof seal is formed therewith, said coating being adapted to permit for variation in expansion and contraction of the insert and condenser tube.

HERMAN SCHULTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,157,107 Bay May 9, 1939 2,195,403 Bay Apr. 2, 1940 2,225,615 Bay Dec. 24, 1940 2,428,932 Fawick Oct. 14, 1947 2,445,273 Kennedy July 13, 1948 2,517,778 Fischer Aug. 8, 1950 

